The effect of spall on Lg waves  

作　　者：何永锋 陈晓非 张海明 

机构地区：[1]School of Earth & Space Sciences, Peking University, Beijing 100871, China,North-west Institute of Nuclear Technology, Xi'an 710024, China [2]School of Earth & Space Sciences, Peking University, Beijing 100871, China

出　　处：《Acta Seismologica Sinica(English Edition)》2005年第3期331-337,379,共8页

基　　金：National Natural Science Foundation of China (40134010).

摘　　要：The generation mechanism of Lg wave from underground nuclear explosion is still not clear at present. The gen-eral viewpoint is that the S wave generated by the near-source scattering of explosion-generated Rg appears to be the primary contributor to the low-frequency Lg (0.2~2.0 Hz) from nuclear explosions. The viewpoint is supported by the analysis of regional data from several Yucca Flats, NTS explosions by Patton and Taylor (1995), who fur-ther indicated that the prominent low-frequency spectral null in Lg is due to Rg from a compensated linear vector dipole (CLVD) source. In the paper, the data from Kazakstan Test Sites are investigated by a spectral ratio method. We have found that the spectral ratio of Lg waves is characterized by a spectral scalloping and a pronounced null, and the spectral null does not shift with spall dwell times, showing a strong dependence on shot depth and a very good agreement with those expected from Rg due to a CLVD source.

关 键 词：spectral ratio SPALL Lg wave CLVD source NULL 

分 类 号：P315.3[天文地球—地震学]